Watchful: Cellular Septic Monitor
Custom cellular septic-system monitor: nRF9160 firmware, mTLS MQTT to a self-hosted broker, CRM dashboard, and SMS alerts when a pump or alarm fails.
Aerobic septic systems fail quietly. A cellular monitor that texts a technician when the air pump or alarm trips turns maintenance contracts from scheduled visits into proactive service.
Watchful is custom hardware and firmware built on a Nordic nRF9160 cellular module. It watches aerobic-system pump pressure and the OEM alarm signal, publishes over mutually authenticated TLS to a self-hosted EMQX broker, and a bridge in the Mac Septic CRM turns failures into SMS alerts and dashboard events.
On 2026-08-26 the fleet moved from a public test broker to the self-hosted broker with certificate-scoped per-device access control. On the bench unit both critical alert paths, air-pump failure and OEM alarm, have fired end to end, including live SMS delivery to a technician's phone.
- > Self-hosted mTLS broker with per-device certificates (2026-08-26)
- > Both critical alert rules proven end to end on bench hardware
- > Dashboard live inside the Mac Septic CRM
- → Resolve cellular connectivity on the bench unit
- → Field pilot on customer systems
- ! Bench-proven only; zero field units deployed
- ! LTE connectivity and a sensor fault still open on the bench unit